Traditionally, newspaper vending machines have been comprised of a cabinet for enclosing a stack of newspapers, the cabinet accessible through a latch-operated, hinged door. A mechanical coin control mechanism for accepting and totalizing coins, releases the latch securing the door, when the coins reach the total denomination required for that day's edition of the newspaper.
Recently, electronic totalizers have been introduced into the field of newspaper vending machines. The function of the electronic totalizer is to electronically sense the denomination of the coins deposited through the slot of the newspaper vending machines and, among other functions, to send an appropriate signal to the latch-release mechanism when the coins reach a predetermined maximum representing that day's price for the newspaper.
The electronic signal must be converted into mechanical motion to release the latch securing the door of the newspaper cabinet. In the past, the conversion of the electronic signal into mechanical motion has been performed by a solenoid. For example, U.S. Pat. No. 5,036,966, the specifications and drawings of which are incorporated herein by reference, discloses in FIG. 8 solenoid (140) which pulls upwardly when electronic power is applied to release the latch.
Applicant has found that the use of a small, D.C.-powered 2.0 volt (minimum) electric motor will provide the same amount of movement to operate the latch release mechanism, but draw less current. The result is a significant increase, as compared to a solenoid operated release mechanism, in the useful life of the power supply. Applicant has found that when the motor is placed in series with a limit or home switch which is located to cut off power to the motor and prevent a lock-up condition, a maximum D.C. current of approximately 75 milliamps is required during the unlock pulse. This compares to 380 milliamps of a solenoid operated latch release mechanism. Both require about 250 milliseconds to affect the necessary movement.
Applicant's experiments determined that the unlock pulse draws approximately 75% of the battery power over the expected normal life of their TK-Electronic R model mech. According to Applicant's calculations, the resulting expected battery life increases from 12-18 months for the solenoid operated unlock mechanism to 24-36 months for the motorized latch unlock mechanism. Moreover, the solenoid has been difficult to adjust in production and its operation may vary over the life of the mechanism. In addition, the cost of the motorized latch release mechanism is about one-half that of the solenoid operated latch mechanism. Thus, using the electric motor-driven latch release as compared to the solenoid-driven latch release can represent a substantial increase in the useful life of the D.C. power supply operating the electronic coin control mechanism. This is especially important in that the environment in which most of the newspaper vending machines operate is one that does not have ready access to a remote power source such as an AC outlet and therefore, the racks must have their own internal power supply.
It is an object of the present invention to provide a retrofit motor-driven latch mechanism for newspaper vending racks as identified and set forth in U.S. Pat. Nos. 3,738,466, 3,882,984, 3,946,848, 4,000,799, and 4,037,701.
These patents set forth newspaper vending rack mechanisms and particularly set forth systems which are able to vend at variable prices. The inclusion of an electronic totalizer means in the mechanical coin control mechanism provides for the removal of some but not all of the mechanical environment. Specifically, the introduction of an electronic totalizer allows for the removal of a mechanical totalizing means, but leaves the mechanical environment which provides for the latch release mechanism, the escrow tray, and the coin release/coin return mechanism.
It is another object of this invention to provide for an electronic coin control mechanism for a newspaper vending machine which provides for an electrically operated motor to disengage the latch mechanism securing the door to the cabinet of the newspaper rack.
It is another object of the present invention to provide for a retrofit motor-driven latch mechanism for a newspaper vending machine which is activated by a pulse from the electronic totalizer and deactivated by a series mounted switch which de-energizes the motor when contacted by an armature mounted rotor arm.
It is another object of the present invention to provide for a retrofit motor-driven latch mechanism for a newspaper rack, the motor of which is energized by a pulse whose duration is electronically determined.